Method of producing wash-fast sized fabrics resistant to shrinkage



Patented May 23, 1939 v UNITED STATES PATENT OFFICE.

METHOD OF PRODUCING WASH-FAST SIZED FABRICS RESISTANT T0 SHRINKAGE No Drawing. Application March 12, 1936, Serial No. 68,540. In Germany January 28, 1936 6 Claims.

This invention relates to methods of producing and using sizing materials that are fast to washing and prevent the fabrics from shrinkmg.

It is known that the sizing materials used in the textile industry, such as starch, glue, gelatine, if desired, in combination with waxes, talcum or other substances, have the tendency to separate from the sized goods during washing, so that the goods become flabby again and reassume the previous unattractive aspect.

In recent years many methods have been devised in .an endeavor to meet this drawback. Most of the same provide for producing artificial resins on the surface of the goods either of the phenol-aldehyde or the urea-aldehyde type.

The application of phenol-aldehyde products is limited due to these products being always more or less colored, so that they can be applied only to dark shade goods.

The urea-aldehyde products can be obtained in colorless condition, but they have very often an unpleasant smell similar to urine, which is plainly noticeable when the textiles having been treated with such products are wet.

Other methods use starch containing sizing materials which are fixed by means of formaldehyde so as to be fast to washing. Although the fasteness to washing of such sizing materials is satisfactory, they can be easily removed from the goods again with the aid of enzymic unsizing means.

It has now been found that sizing materials of an excellent fastness to washing can be obtained by incorporating in the textile, partial condensation products from acetone or other ketones together with aldehydes and completing the condensation to the water insoluble condition in situ. Sizing materials of this type are colorless and odorless. It is a surprising fact that textiles which are sized with such products shrink not at all or only to a very small extent during washing and are thus proof against shrinking.

The method according to this invention is so carried into effect'that, at first, a water-soluble partial condensate is produced from acetone and formaline by means of which the textile is im- This partial or half-condensation product, the

production of which per se forms part of the present invention, is obtained by substituting sodium carbonate for caustic soda as a catalyst in reacting the acetone and aldehyde. It is surprising that,'at room temperature, in the presence of calcined soda no reaction at all sets in, not

even if allowed to stand for a considerable length of time. But by heating to a temperature of 50 to C., a vigorous reaction sets in which comes to an end only after the alkali is completely dissolved. The reaction can, howeverybe interrupted, Whenever desired, by cooling down. Thus, without extra heating, the reaction cannot set in again, so that it is possible to obtain the halfcondensate previously referred to in liquid state by regulating the heat supply and dosing the amount of soda added.

Acetone and formaldehyde alone do not react with one another. In presence of alkaline catalysers, however, reaction sets in. Depending upon the catalysers andv the temperature chosen different products are obtained.

These sizing baths may be combined with other sizing materials. By adding softening or filling material various effects can be obtained. The application of water repellent agents, as emulsions of paraifin or fats, results in a considerable resistivity against staining by dripping.

Since by the drying and the hot after treatment all moisture is removed from the textile fibres, it is necessary to apply a further after treatment. It is also necessary 'to remove the excess of alkali unless the sizing solution is neutralized prior to being applied.

Example 1 To five parts of acetone and 25 parts of for- I can be dispensed with. The fabric is then acidulated to remove the alkaline residues, soaped, if desired and finished in usual manner.

Example 2 50 parts of acetone, 250 parts of formaline of v 40% concentration and 15 parts of calcined soda are supplied into a double-walled vessel which is provided with steam heating and water cooling means. The mass is cautiously heated to 50 to 60 C. by means of which the soda is dissolved. Without requiring further heating the solution boils up vigorously by itself and the partially condensed water soluble resin is formed. Upon the termination of the reaction, the solution is diluted with water in the proportion of 1:1 and then a bleached, mercerized and colored cotton. fabric is impregnated therewith, squeezed out and dried during 20 minutes at 130 C. to complete thecondensation so that the resin is made insoluble in water. Thereupon the fabric is freed from the alkali by acidulation, rinsed, soaped and finished in usual manner..

Example 3 An initial mixture of the same composition as in Example 2 is neutralized with formic acid on the termination of the partial condensation and diluted with water in the proportion of 2:1. The textileis then impregnated with this solution and dried and the condensation completed at 130 C. Removing the acid after the drying can be dispensed with. The fabric is rinsed with water and finished in usual manner.

What we claim is:

1. The method of sizing fabric to render it resistant to shrinkage and fast to washing without altering its color or imparting odor essentially consisting in forming a partially condensed artificial resin which is colorless and odorless when fully condensed by mixing acetone and formaline substantially in the proportions of one part acetone to five parts formaline of 40% ccncentration in the presence of an alkaline catalyzer, impregnating a fabric with the partially condensed mixture, and completely condensing the resin in the fabric so as to be fast to washing.

2. The method of sizing fabric to render it resistant to shrinkage and fast to washing without altering its color or imparting odor essentially consisting in forming a partially condensed artificial resin which is colorless and odorless when fully condensed by mixing acetone and formaline substantially in the proportions of five parts acetone to twenty-five parts formaline of 40% concentration, adding approximately seven parts f concentrated caustic soda lye while maintaining the mixture so produced cooled to a temperature lower than room temperature, impregnating a fabric with said cooled mixture, and raising the temperature of the impregnated fabric to substantially room temperature to condense the resin to water-insoluble condition.

3. The method of producing wash-fast sized textile fabric resistant to shrinkage essentially consisting in forming a partially condensed resin which is colorless and odorless when fully condensed by mixing approximately 50 parts acetone with approximately 250 parts formaline of 40% concentration and approximately 15 parts of calcined soda, raising the temperature of the mixture to between 50 C. and C., diluting the solution so produced with approximately an equal quantity of water, impregnating a. textile with the solution and drying the impregnated textile at a temperature between C. and C. to fix the resin so as to be fast to washing.

4. The method of producing wash-fast sized textile fabric resistant to shrinkage consisting essentially in forming a partially condensed water-soluble artificial resin which is colorless and odorless when fully condensed by mixing approximately 50 parts acetone with approximately 250 parts formaline of 40% concentration and approximately 15 parts of calcined soda, raising the temperature of the mixture to between 50 C. and 60 C., diluting the solution so produced with approximately an equal quantity of water, impregnating a textile with the solution, drying the impregnated textile at a temperature between 100 C. and 150 C. to fix the resin so as to be fast to washing and freeing the textile of alkaline residues.

5. The method of producing wash-fast sized textile fabric resistant to shrinkage consisting essentially in forming a partially condensed water-soluble artificial resin which is colorless and odorless when fully condensed by mixing approximately 50 parts acetone with approximately 250 parts formaline of 40% concentration and approximately 15 parts of calcined soda, raising the temperature of the mixture to between 50 C. and 60 C., neutralizing the partially condensed solution with formic acid, diluting the neutralized solution with water in ma proportion of 2 to 1, impregnating a textile with the diluted solution, and drying the impregnated textile at a temperature between 100 C. and 150 C. to fix the resin so as to be fast to washing.

-6. The method of producing wash-fast sized textile fabric resistant to shrinkage consisting essentially in forming a partially condensed water-soluble artificial resin which is colorless and odorless when fully condensed by mixing acetone and formaline substantially in the proportion of. one part acetone to five parts formaline of 40% concentration together with calcined soda as a catalyzer, and raising the temperature of the mixture; impregnating a fabric with the partially condensed resin, and continuing the heating to complete the condensation of the resin in the textile so as to be fast to washing.

KASPAR ZWICKY. FRIEDRICH BRUNNER. 

